Special hearing on potential environmental health factors associated with autism spectrum disorders

Autism Speaks comments on state of research on potential environmental health factors with autism following US Senate committee on environment and public works, subcommittee on children's health

Autism Speaks' Chief Science Officer Geraldine Dawson, Ph.D. emphasized the importance of research on environmental risk factors for autism spectrum disorders as the U.S. Senate Committee on Environment & Public Works, Subcommittee on Children's Health convened a special hearing on potential environmental health factors associated with autism spectrum disorders (ASD) and related neurodevelopmental disorders. The hearing is examining the latest research on potential environmental factors that may increase the risk for autism spectrum disorders.

As this hearing reviews studies funded by the Environmental Protection Agency and the National Institute of Environmental Health Sciences on environmental factors associated with autism, including toxins and other factors that can influence brain development, Dr. Dawson reiterated that it is important to remember that, "Although genetic factors clearly contribute to the causes of autism, we also need to understand environmental factors and their interactions with genetic susceptibility."

The dramatic increase in autism prevalence over the last decade - increasing 600 percent in the last two decades - underscores the need for more research on environmental factors. "Our understanding of typical brain development combined with what we've learned from examining the brains of individuals with autism indicates that it is important to investigate the roles of the prenatal and early postnatal environment," explains Dr. Dawson. "To investigate environmental factors that may be active during this time, researchers are casting a wide net on potential environmental agents that can alter neurodevelopment, including exposure to infection, pesticides, and chemicals."

One of the ways that researchers are looking at interactions between the environment and genetic susceptibility is through epigenetics. Epigenetics refers to changes in the expression of genes caused by mechanisms other than changes in the underlying sequence of DNA. Through epigenetic mechanisms, environmental factors can change the way each bit of genetic code is read, amplifying the product of a certain piece of code while turning off another such that it is not read at all. The notion that environmental factors can have such dramatic effects on how DNA is read makes research on epigenetics an important priority.